Can someone help me to understand just how the wastegate operates on my
83 W123 Benz I5 Turbodiesel.
I assume the following: (correct me if I'm wrong)
The hose going from the intake (high pressure) side of the turbo goes
to the wastegate on the exhaust side of the turbo. I think this
wastegate operates like a pop valve... The turbo boosts to a high
threshold pressure causing the wastegate to open. This allows excess
pressure to escape into the exhaust. Then the turbo slows and the boost
pressure drops to a low threshold causing the wastegate to close.
I did an experiment today to see if my analysis of the system was
correct. I unhooked the hose to the wastegate and held my finger over
it with the engine running. Then I revved it very gently... Just enough
to get the turbo to spool very slightly. I felt a little pressure
Next I wanted to see just how much power I would lose by unhooking this
hose and driving the car. To my surprise, the engine performance did
not change drastically. I did notice that I had the acceleration was
much more linear. That makes sense because there was no wastegate to
stay closed until the high threshold pressure was reached. Unhooking
the hose simulated having the wastegate open all the time.
I actually liked the performance without the wastegate. That "power
surge" form 1st to 2nd gear was greatly softened. This also feels like
it is not as hard on the transmission during the 1st to 2nd shift.
There is not as much torque at that instant.
I also enjoyed the "psssssh" sound since the hose was venting under the
hood and not into the exhaust anymore.
I am really thinking about getting a boost gauge hooked up to the
intake so I can tweak the boost. I am planning on installing a valve on
this hose and venting the hose into the engine compartment. This way I
can adjust the max boost to about 12 PSI. The smaller the leak, the
more boost and vice versa. I also like a more linear power distribution
and the noise :)
Any input is welcome. I would like to know if anyone else has done